Direct-acting steam-engine for reciprocating sawmill-carriages



v (No Model) W. E. HILL.

DIRECT AGTING STEAM ENGINE POE REGIPROGATENG SAWMILL OARRIAGES. No.531,532. 1 ted Dec. 25, 1894.

Inventor- (UNITED STATES-'- PATENT OFFICE.

WILLIAM E. HILL, on KALAMAZOO, MICHIGAN.

DIRECT-ACTING STEAM-ENGINE FOR RECIPROCATING SAWMILL-CARRIAGES.

SPECIFICATION forming part of Letters Patent No. 531,532, dated December25, I894. Application filed February 1893. Serial No. 463,758- (Nomodel.)

To all whom it may concern:

Be it known that I, WILLIAM E. HILL, a citizen of the United States,residing at the city of Kalamazoo, in the county of Kalamazoo and Stateof Michigan, have invented certain new and useful Improvements inDirect-Act ing Steam-Engines for Reciprocating Sawmill-Carriages, ofwhich the following is a specification.

My invention relates to improvements in direct acting steam engineshaving very long steam cylinders such as are used for steam feed forsaw-mills. r

The object of my invention is to provide in addition to a steam cushionautomatic means of relieving the pressure ofsteam back of the pistonhead and so leave only the momentum of the carriage and piston to beovercome by the steam cushion in the end of the engine cylinder and thebufier. I accomplish these results by the mechanism shown in the ac-fcompanying drawings, in which j Figure l, is aside view of my inventionas applied to a steam feed for saw-mills where no butter is used. Onlythe forward end of the engine is shown and that in sections. Fig.2,shows a side view of my invention as I prefer to apply it where abufler is used. Here also only the end of the engine is shown insections.

Similar letters of reference refer to similar parts throughout bothviews.

, A, A, are the floor and floor timbers of a saw-mill.

A, is the end of the steam cylinder of a steamfeed for saw-mills, aportion being cut away from the side, showing the piston head B, withits piston rod B passing through a stuffing box at the end. The pistonrod B connects by the bracket 0 to the saw-mill carriage O, the engineoperating to recipro- T cate the carriage.

The pipe G is the inlet pipe and H is the outlet pipe of the front endof the steam cylinder.

G is a check valve that stops the escape of steam from the cylinder thusforcing the steam to exhaust through pipe H. A cushion of steam willthus be formed between the piston head B and the head of the cylinder A,when the piston head B passes the exhaust port. This cushion overcomesthe momen tum of the carriage withouta'jar.

My invention providesa means whereby need to be used when the pistonhead B is compressing the steam cushion in the end of the cylinder. Itwill be operative at any point back of the piston head however.

The arm I) of the valve Dis connected by the connecting rod 0 to thebell crank 11 which is connected by the connecting rod e to the I arm 25of the lever E. l r

The lever E is operated by the pin a striking against the arms 1' and'r', the valve being opened by the pin a striking the arm 1- when thepiston is near the end of its stroke and closed by its striking the arm0 as soon .as it returns. It will thus'be seen that when the enginebecomes unmanageable or for any reason is operated with too greatviolence, the steam is allowed to escape from the cylinder through thepipe D and so relieve the pressure on the back of the piston head atonce whether the engine is reversed or not. When the momentum of theparts is overcome the compressed steam in the end of the steam cylinderA will cause the carriage to return sufficiently far to closethe valveD.

In Fig. 2, I show the plan I prefer for operating the valve D when usedin combination with my improved steam buffer, described in myapplication for a patent filed in the Patent Oflice February 13, 1893,Serial No. 462,167. The connecting rod e is there connectedto the arm ofthe engine valve of the buffer and the Valve D is operated when thebumper comes into operation.

7 Another exhaust pipe and valve the same asD and D couldbe operatedwhen the piston head approached the rear of the cylinder. This extraprecaution will not be required except where a very large engine is usedor the carriage is very heavily weighted.

I do not wish to be confined to the exact mechanism here shown foroperating the valve D as many variations will readily suggest themselvesto those skilled in the art of constructing engines, and the form of thevalve D may also be greatly varied. It is also clear that the exhaustport will have the effect if combined with the steam cushion in the endof the cylinder or with the buffer alone or with the steam cushion inthe end of the cylinder and the buffer together. The exhaust pipe D andvalve D would be of great utility where neither the steam cushion in theend of the steam cylinder nor bumper were employed to prevent the jar.Of course any other vapor besides steam, or gas under pressure could beused to operate my engine.

I have an application in the Patent Ofiice, filed February 25, 1893,Serial No. 463,759, for a device similar to the one here described,which is of slightly different construction. A safety exhaust pipecontaining a check valve opens into the steam cylinder a little morethan the length of the piston head from the end of the steam cylinderand is connected with the engine valve and in that way effects the samepurpose which my invention shown in this application accomplishes.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-- 1. In a direct acting engine of the classdescribed the combination with a steam cylinder and piston of an exhaustpipe containing a valve, a stop on a moving part of the mechanism, alever which is connected with the valve stem with which said stop coactsto exhaust the steam from behind the piston head and relieve thepressure for the purpose specified.

2. In a direct acting steam engine of the class described an exhaustpipe containinga valve with suitable mechanism for operating the same bya stop on a moving part of the engine adapted to be opened to relievethe pressure of steam back of the piston head when the head compressessteam confined in the end of the cylinder and adapted to close saidvalve when the piston head recoils, for the purpose specified.

3. In a direct acting steam engine an exhaust pipe containing a valveoperated by suitable mechanism in connection with a stop on a movingportion of the engine, said exhaust pipe connecting with the steamcylinder so as to open back of the piston head when the piston headcushions on steam confined in the end of the cylinder for the pur- 6opose specified.

4. In a direct acting engine the combination of the steam cylinder A,the inlet pipe G, containing the check valve G, the exhaust pipe II andthe exhaust pipe D containing the valve D a stop on a moving part ofsaid mechanism, a lever which is connected by connecting rods and bellcranks to the arm I) of the valve D and in position to be actuated bysaid stop, substantially as described for the purpose specified.

In witness whereof I have hereunto set my hand and seal in the presenceof two witnesses.

WILLIAM HILL. [n 3.

Witnesses:

E. S. Roos, CORA WESTBROOK.

